Photographic material



May 16, 1939. A. MURRAY PHOTOGRAPHIC MATERIAL Original Filed May 24,1934 LIGHT SENSITIVE RES/S T METAL FOIL RUBBER \ZSUPPORT ATTORNEYS.

Patented May 16, 1939 UNITED STATES PATENT OFFICE PHOTOGRAPHIC MATERIALJersey Original application May 24, 1934, Serial No.

Divided and this application Decemher 7, 1935, Serial No. 53,381

3 Claims.

This invention relates to a photographic element which may be used formaking etched designs on glass and metal objects, such as bowls,tumblers, vases, cylinders, stem-ware, and the like.

This case is a division of application Serial No. 727,304, filed May 24,1934, now Patent N0. 2,073,313, issued March 9, 1937. i

It has been difficult to make deeply etched or cut designs of uniformlyhigh quality upon the surface of solid objects such as stem-ware, exceptby processes requiring a large amount of time consuming and highlyskilled hand work. I have invented a method of etching such glasswareina simple and comparatively inexpensive manner. This comprises theformation on a freely extensible sheet, such as rubber, of an image thatis extensible with the rubber and applying this image bearing stencil ornegative, preferably in the form of a closed or tubular band, to thesurface of the object to be etched, which also carries a sensitivecoating. This is then exposed to uniform illumination from all sides,the negative removed, and the glass or metal etched by a photoengravingprocess.

My invention resides in the various methods herein described ofmakingthe elastic stencil, in

the sensitized elastic element, and in the completed elastic stencilband.

Reference will be made to the accompanying drawing, in the severalfigures of which like numerals represent like parts and in which:

Fig. 1 is a section on an exaggerated scale of a. sensitized elementmade according to my invention.

Fig. 2 is a similar section of the element after exposure and removal ofthe resist at the exposed portions.

Fig. 3 is a section of the element after etching.

Fig. 4 is a section of the element after appli cation of a dye thereto.

Fig. 5 is a section of the elastic sheet bearing the dye design, afterremoval from the support.

Fig. 6 is a perspective view of a frame carrying an endless rubberstencil strip.

Fig. '7 is a similar view showing the band expanded to permit insertionof a goblet to be ornamented.

Fig. 8 is a similar view showing the goblet and band in position forprinting.

It is obvious that a prime desideratum in a photographic negative orstencil having a highly flexible or elastic base is that the image shallbe fully as extensible and flexible as the support. This is not the casewith ordinary photographic emulsions of gelatine, collodion or the like,and the image, if formed originally in such a layer. must be printed orstenciled upon the support itself and the original layer removed.

I will first describe my preferred method of forming such a stencil ornegative, reference being made to Fig. 1.

Upon a suitable support I which may be a glass plate, a sheet of acellulosic derivative composition, waxed or otherwise waterproofed,cardboard or any other reasonably rigid sheet, a thin, elastic, soft,translucent, vulcanized rubber sheet 2 is temporarily attached by meansof a suitable stripping adhesive, such as wax or a rubber cement. Therubber sheet would be held smoothly but ordinarily not under tension. Asuitable cement is a .5% solution of rubber in benzene.

Commercial rubber sheeting having a thickness of .003-.004 inch ispreferred but the thickness may vary within wide limits, as between.0005 and .01 inch.

A thin, preferably unelastic stencil material 3.

as for'instance, a sheet of brass, nickel or other metal foil .001 inchthick, is then attached to the rubber layer by means of a rubber cement.If the element is to be used immediately, brass is preferred, but sincebrass tends to affect rubber if kept in contact with it, nickel or someother inert material would be used if the plate is to be stored for sometime.

To the sheet of foil 3 is then applied a coating 4 of a light sensitiveresist, an example being the following:

- .Grams Dicinnamal acetone 32.5 Syrian asphaltum 97.5 Phenol 1.80Solvent naphtha (coal tar) 500.0 Toluene 270.0

element after this treatment is illustrated in Fig. 2. the resist beingindicated by 4.

The stencil sheet is then etched in the exposed parts of the design withaqueous ferric chloride solution of above 86 Baum until the brass isremoved to the rubber which the etching solu tion does not affect. Theelement then appears .as shown in Fig. 3, the etched brass sheet beingindicated at 3'. After rinsing with water and drying, the etched surfaceis treated with a stain, solution or dye which deposits upon the areasof rubber laid bare by etching, a coloring matter which becomesphysically extensible with the rubber, as indicated at 5 in Fig. 4. Thismay be a rubber ink" or stain, sprayed or brushed upon the stencil andcoating the rubber in the stencil openings. This solution may consistof:

Grams Nigrosine (Schulz No. 985)-; 5 2% crepe rubber in benzene 30 Ether65 thereto by a stripping layer, separates from it.

There is now left a rubber sheet 2, as shown in Fig, 5, having theproperties already enumerated and carrying susbtantially integral withit and extensible with it, a light absorbent or obstructive pattern5'-formed as a result of a photographic process.

A second method of making'the negative is by applying to the rubberlayer a bichromated fish glue solution of familiar type such asPhoto-engraving glue (fish glue) grams 360 Ammonium bichromate do 55Water liter 1 When dry, the plate is exposed to a suitable light design,the print developed by washing in water, and dried. It is now coveredwith a suitable stain such as the one already described, or

Grams Oil Red C dye (Schulz No. 532) 1 Nigrosinei 4 1.0% rubber solutionin benzene 20 When dry, the rubber sheet is stripped from the temporarysupport and washed in warm water to remove the remaining glue. This isaided by stretching the rubber. There is left a rubber sheet carrying astain, which ordinarily will be a line image.

A third method, which is non-photographic, of making the rubber negativeor positive will now be given. The rubber sheet is placed over a designto be copied. The rubber sheet may be either mounted on a glass sheet asbefore or placed tightly on the design on a drawing board and both heldin place by thumb tacks. The design or pattern is then drawn in watercolor on the rubber by hand using a suitable fine brush.

When dry it is stained with dye solutions of the type already described.The water color is then washed off leaving the stain image.

Still 'a fourth method is the following. A rubber sheet, mounted asbefore, is coated with a silver halide-gelatine emulsion, exposed to alight image of the design, and developed in a tanning developer of knowntype, such as pyro. The untanned gelatine is removed by washing in warmwater. After drying the negative is stained as above described and theremaining tanned gelathan another.

tine stencil removed by any usual means that does not attack the rubberor the stain.

By whichever method isused, there is obtained an elastic negative,' thesupport of which is a thin, elastic, soft, translucent, vulcanized sheetof rubber carrying a perfectly extensible design in or on its surface,and which stretches and contracts with the rubber support withoutcracking or peeling. Numerous uses. of such a negative at once suggestthemselves. It may be used for making distorted or cartoon pictures byextending the rubber sheet more in one direction The effects of motion,useful in making animated cartoons, may be made by constantly changingthe extension of the rubber in one or more directions or unevenly. Ifextended uniformly in all directions, an enlarged print may be made bydirect contact printing.

By stretching to a precisely determined degree, a negative havingcalibration marks on it may be used in the calibration of individualinstrument scales where the same scale readings are shown but insomewhat different dimensions on the several instruments.

The principal use which I have in mind, however, is the printing ofphotographic designs upon the surface of an object having other than aplane surface.- Such objects may be glass-ware, such as bowls, tumblers,jars, stem-ware including goblets, wine glasses and vases, and otherdishes; metal cylinders used in printing processes or for any otherpurpose; molded metal forms, such as picture frames, convex dials, watchcases and furniture parts and other objects too numerous to catalog. Ingeneral the print would be made by stretching the negative over oraround the object to be ornamented or marked and which would carry uponits surface a light sensitive coating. The rubber sheet would by its owntension hug closely and contact the surface of the object except forconcavities. The first photographic image could be the permanent one ifthe object were not to be subjected to rough usage but the coatingusually would be of a type adapted to act as a resist, andafter-exposure, would be developed by a wash-off or solvent process,leaving a resist design through which a suitable etching fluid could acton the metallic or glass object, after which the resist would beremoved. The particular resist used would have to be one capable ofwithstanding the etching fluid used. Many such are known for use withmetallic surfaces but few photographic resists are known prior to myinvention capable of withstanding the action of hydrofluoric acidordinarily used for glass etching.

Reference will nowbe made to Figs. 6, 7 and 8 which show a device forapplying the negative to the surface of an object such as a goblet. Anegative strip l0 bearing a repeat design II, has its ends secured by asuitable rubber cement in an air tight seam I2, thus forming an endlessor cylindrical rubber negative, the size of which, when unextended, isless than the article to be etched or ornamented. The edges of thisnegative are secured between clamping blocks of a suitable frame. Thisframe consists of a glass cylinder I3 having tightly fitting metal orrubber annular rings 14 and IS in its opposite ends. These rings havecut out annular rabbetswithin which fit smaller rings IS on their outersurfaces. The ring I6 is removed from ring l4 and, while one edge of thenegative band is held stretched, is replaced, clamping the edge betweenthe rings l4 and Hi. The other edge of the band is then clamped to thering l in a similar way. The normal position of the band is shown inFig. 6. Through the ring l5 pass two tubes I1 and I8, with stop cocks I9and 29, the first tube being connected to a source (not shown) ofcompressed air or, preferably, of a compressed inert gas and the otherto a suction device (not shown), or both may be connected to acirculating supply of an inert cooling fluid. When the stop cook 20 isopened and the cock l9 closed, air will be with drawn from the annularspace between the glass cylinder I3 and the rubber negative l0 and thelatter will be drawn outwardly as shown in Fig. 7. The goblet 2| orother article carrying a sensitive coating on that portion of itssurface to be ornamented is then placed within the casing as shown inthe same figure and stop cock l9 opened while 20 is closed.

Even if the tube I! were open to the air, the

contraction of the rubber negative band I I would I tinuously exposed,tends to deteriorate rapidly For this reason I prefer to use an inertfluid rather than air and to circulate this through the space betweenthe rubber negative and the glass cylinder. This fluid may be an inertgas or a liquid such as water.

The whole device containing the article 2| is then rotated at a uniformrate before a light source for as long a time as maybe required for theexposure, depending on the intensity of the light and sensitivity of theparticular coating on the article 2h The light passes through the glasswhich is unobstructed and through the negative producing a print on thesensitized surface.

It is to be understood that the description and formulae herein givenare by way of example and that I consider as included within myinvention not only all of the subject matter herein disclosed but alsoall modifications and equivalents thereof that fall within thereasonable scope of the appended claims.

, Having thus described myinvention, what I claim as new and desire tosecure by Letters Patent is:

l. A sensitized element comprising a thin, translucent, elastic sheet ofvulcanized rubber, a thin layer of metal foil removably secured to onesurface of the rubber sheet and a photographically sensitive layer oversaid metal foil.

2. A sensitized stripping element comprising a rigid support, a thin,translucent, soft, elastic, vulcanized rubber sheet secured thereto by astripping layer, a resist layer applied to the rubber sheet and aphotographically sensitive layer applied to the resist layer.

3. A sensitized stripping element comprising a rigid support, a thin,translucent, soft, elastic, vulcanized rubber sheet secured thereto by astripping layer, a thin layer of metal foil removably secured to therubber sheet and a photographically sensitive layer applied to the metalfoil.

ALEXANDER. MURRAY.

